The present invention relates to a pipe machining tool. More particularly, the present invention relates to a portable pipe machining tool that selectively simultaneously cuts a pipe and scrapes and finishes a longitudinal outer surface of the pipe that has a pair of ends so as to facilitate bonding of the pipe wherein the portable pipe machining tool is supported only by the pipe it is machining and access to the pair of ends of the pipe is not required. The portable pipe machining tool includes a fixed cylindrically-shaped frame that is fixedly attachable to a portion of the pipe, a rotatable cylindrically-shaped frame that is rotatively connected to the fixed cylindrically-shaped frame and is rotatably attachable to an adjacent portion of the pipe, a parting tool assembly that extends radially along the rotatable cylindrically-shaped frame and is selectively engagable and disengagable, and when engaged has a portion thereof moving radially inwardly through the rotatable cylindrically-shaped frame and progressively cutting into the adjacent portion of the pipe as the rotatable cylindrically-shaped frame rotates relative to the fixed cylindrically-shaped frame until the pipe has been cut, and a scrapping and finishing tool assembly that extends radially along the rotatable cylindrically-shaped frame, diametrically opposing the parting tool assembly, and is selectively engagable and disengagable, and when engaged has a portion thereof moving longitudinally through the rotatable cylindrically-shaped frame and longitudinally along the longitudinal outer surface of the adjacent portion of the pipe and scraping and finishing the longitudinal outer surface of the adjacent portion of the pipe as the rotatable cylindrically-shaped frame rotates relative to the fixed cylindrically-shaped frame so as to facilitate the bonding of the pipe, and is selectively simultaneously operable with the parting tool assembly if so desired, so as to cut, scrape, and finish the adjacent portion of the pipe simultaneously as the rotatable cylindrically-shaped frame rotates relative to the fixed cylindrically-shaped frame.
The days of cast-iron pipe have passed in fluid distribution systems for utilities, such as heating gas distributors. Today, plastic pipes are universally used. They are cheaper, lighter, can be joined by simple heating techniques, and deteriorate at a much slower pace than metal pipes.
In the repair and replacement of equipment associated with plastic pipe lines, it is frequently necessary to cut the pipe and thereafter, prepare the end of the pipe, with the pipe end preparating operations involving one or more of facing, turning, profiling, threading, or beveling. Equipment has existed for cutting the pipe and performing other operations on the pipe, such as beveling the end preparatory to making a weld connection to the pipe end.
Motor driven pipe cutting machines are known and generally include a base or fame structure having rollers which support a pipe to be cut and a motor driven cutting wheel mounted on the frame for displacement into engagement with the pipe to cut the same.
Use in the field of motor driven pipe cutters heretofore available is difficult as a result of the structural complexity and unitary construction of the pipe cutters. More particularly in this respect, the pipe cutter has to be transported to the point of use, such as in a truck, and then removed from the truck and setup on the ground or other underlying support surface for operation.
The size and weight of the pipe cutter can make the loading and unloading thereof relative to the transport vehicle physically difficult for the workman and require the use of special loading and unloading elevators or hoists as well as wheeled dollies or the like to facilitate ground transportation of the pipe cutter to the specific point of use. 5 In some pipe cutters, displacement of the cutting wheel is achieved by a hand operated lever which affords control of the cutting force by the operator, but such hand operation is physically fatiguing, whereby optimum force and cutting speed is likely to progressively decrease in connection with continuous use of the cutter by the operator.
Another disadvantage of prior pipe cutting machines resides in the difficulty in obtaining a quality cut and maintaining quality from one cut to another. In this respect, a quality cut requires that the axis of the pipe by maintained parallel to the axis of the cutting blade, so that the cut is in a plane transverse to the pipe axis.
Generally, the pipe to be cut is supported on rollers beneath the cutting blade and on an adjustable support spaced from the cutting machine. The latter support is adjusted laterally in an effort to align the pipe and cutting wheel axis, but the desired parallel relationship therebetween is extremely difficult to obtain and/or maintain from one cut to another. Any misalignment with respect to desired parallel relationship between the pipe and cutting wheel axis reduces the quality of the cut obtained, whereby considerable time and effort are spent to initially make the necessary adjustments of the adjustable support to assure as accurate alignment as possible, and frequent checking of the alignment is necessary in an effort to maintain the best possible alignment.
The use of portable end prep lathe, either in the field or in a shop, for performing a variety of machining operations on a pipe is well known in the art.
The end prep lathe is mounted concentrically with the pipe by means of a mast having a chuck or mandrel which is positioned within the pipe and is adjusted to lock into the pipe, with the mast extending outwardly therefrom and mounting a frame or housing and a rotatable tool head. The tool head is rotatable by means of a motor, such as a hydraulic or air motor.
In one type of machine, the advance of the tooling on the tool head towards the pipe as well as the axial movement of the frame and the tool head axially of the pipe, determines the angle of the bevel cut on the pipe. Without axial movement of the tool head and frame, there can be a cut-off or facing operation. It is known to achieve a bevel cut by use of a portable end prep lathe wherein the frame and tool head are advance axially by rotation of a hand wheel.
Numerous innovations for pipe machining tools have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention in that they do not teach a portable pipe machining tool that selectively simultaneously cuts a pipe and scrapes and finishes a longitudinal outer surface of the pipe that has a pair of ends so as to facilitate bonding of the pipe wherein the portable pipe machining tool is supported only by the pipe it is machining and access to the pair of ends of the pipe is not required. The portable pipe machining tool includes a fixed cylindrically-shaped frame that is fixedly attachable to a portion of the pipe, a rotatable cylindrically-shaped frame that is rotatively connected to the fixed cylindrically-shaped frame and is rotatably attachable to an adjacent portion of the pipe, a parting tool assembly that extends radially along the rotatable cylindrically-shaped frame and is selectively engagable and disengagable, and when engaged has a portion thereof moving radially inwardly through the rotatable cylindrically-shaped frame and progressively cutting into the adjacent portion of the pipe as the rotatable cylindrically-shaped frame rotates relative to the fixed cylindrically-shaped frame until the pipe has been cut, and a scrapping and finishing tool assembly that extends radially along the rotatable cylindrically-shaped frame, diametrically opposing the parting tool assembly, and is selectively engagable and disengagable, and when engaged has a portion thereof moving longitudinally through the rotatable cylindrically-shaped frame and longitudinally along the longitudinal outer surface of the adjacent portion of the pipe and scraping and finishing the longitudinal outer surface of the adjacent portion of the pipe as the rotatable cylindrically-shaped frame rotates relative to the fixed cylindrically-shaped frame so as to facilitate the bonding of the pipe, and is selectively simultaneously operable with the parting tool assembly if so desired, so as to cut, scrape, and finish the adjacent portion of the pipe simultaneously as the rotatable cylindrically-shaped frame rotates relative to the fixed cylindrically-shaped frame.
FOR EXAMPLE, U.S. Pat. No. 4,411,178 to Wachs et al. teaches a pipe end preparation machine that includes a frame supportable in oriented relation from and beyond an end of a pipe. A tool head is mounted on the frame for rotation about an axis. A tool slide is mounted on the tool head for carrying a tool for movement along a path radial to said axis. A drive mechanism includes a remotely controllable motor for advancing the tool toward the pipe end to provide axial feed for the tool. And, a drive mechanism for advancing the tool slide to provide radial feed for the tool including a remotely controlled motor which can be controlled to vary the radial feed rate in a continuous controlled manner. The remotely controllable motors for radial and axial feed of the tool permit other operations. Circular interpolation effectively provides a third tool axis of movement as provided by the two axes of movement derived from the radial and axial feed.
ANOTHER EXAMPLE, U.S. Pat. No. 4,677,884 to Kwech et al. teaches a portable end prep lathe having presettable mechanical structure operable in response to rotation of a tool head for controlling the angle of a bevel cut on a pipe. A frame is supported relative to a pipe by a mast having a threaded section. The frame carries a rotatable tool head having a tool slide movable to advance a tool radially of the mast. The rate of radial advance of the tool slide is controlled by cam and cam follower structure mounted on the frame and tool head, respectively, and with the number of cams controlling the rate of advance per revolution of the tool head. The tool head is advanced axially of the mast and a pipe by means responsive to rotation of the tool head, including a star wheel mounted on the frame and drivingly connected to a nut threaded on the threaded section of the mast. The tool head has a plurality of circumferentially-spaced actuator pins for coaction with the star wheel to cause indexing thereof as the tool head rotates and resulting axial movement of the tool head, whereby with the radial advance of the tool slide, a bevel is cut on the pipe. The angle of the bevel can be determined by the number of actuator pins that are operable in each rotation of the tool head to index the star wheel and, if a lesser number than all of the actuator pins is initially used, additional actuator pins can be rendered operative during the machining cycle, without stopping the machine, to increase the axial feed and, therefore, the angle of the bevel that is cut on the pipe.
STILL ANOTHER EXAMPLE, U.S. Pat. No. 5,020,401 to Jiles teaches a universal tool for inspecting and processing plastic pipe includes a cylindrical chamfering element with a cylindrical wall and a pipe-receiving opening therein terminating in a base ring, the base ring carrying a tapered pin having an axis parallel to the axis of the cylindrical chamfering element, the wall of the chamfering element having a slot therein proximate the tapered pin and a four-edged cutting element mounted on the outer surface of the cylindrical wall and having one edge of the cutting element protruding through the slot in proximity to the tapered pin, the pipe to be chamfered being forced into contact with the cutting edge by axial pressure on the chamfering element and rotation thereof, an ovality-gage being carried by the chamfering element and being arcuatley rotatable, at the end of the arc rotation of the gage causing rotational forces to be applied to the chamfering element, i.e., the ovality-gage acting as a handle for the chamfering element. The ovality-gage may be separated from the chamfering element and utilized alone or in combination with a coupled second ovality-gage for checking the ovality of pipes of different nominal diameters. A wall thickness gage is carried by the ovality tool whether it is alone or in combination with a chamfering element or a dual ovality-gage.
STILL ANOTHER EXAMPLE, U.S. Pat. No. 5,261,301 to Babb et al. teaches a portable pipe cutting machine comprises a frame, an arm having opposite ends and supported on the frame for pivotal movement about a pivot axis between the opposite ends, a cutting wheel rotatably mounted on one of the ends of the arm, and a hydraulic piston and cylinder unit between the frame and the other end of the arm for pivoting the arm to displace the cutting wheel toward a pipe to be cut which is supported on rollers mounted on the frame beneath the cutting wheel. A manually operable variable displacement pump delivers fluid under pressure to the piston and cylinder unit to displace the arm toward the pipe, and an electric drive motor unit is supported on the arm for displacement therewith and includes an output end axially slidably interengaged with a drive shaft for the cutting wheel.
FINALLY, YET ANOTHER EXAMPLE, U.S. Pat. No. 5,304,018 to LaVanchy et al. teaches a universal plunge cutter for plastic pipe, pipe couplings, plastic flanges and other planar members, is provided. The plunge cutter has a cylindrical body supporting cutters, a drive shaft, a pilot mandrel for guiding the cylindrical body. The cutters are adjustably mounted in cutter slots formed in the cylindrical body so that the cutters present forwardly facing cutting edges which lie skewed relative to a radius of the cylindrical body. A method for the use of the plunge cutter is also provided.
It is apparent that numerous innovations for pipe machining tools have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.